One of the biggest ones I've corrected is taking an active role in their education. My parents would get so mad at me when I got bad grades. I'd constantly get grounded and told you can do better, or literally slapped up the side of the head. But my parents never asked me if I had homework or tests coming up.
If I asked for help with my homework my dad would talk down to me and be like, why don't you get this. It took me running away from home at 15 to finally get sent to a doctor and low and behold get diagnosed with ADHD.
My wife had a similar, but thankfully a less physical situation. Her mom would ground her if she got a bad grade. But she got straight A's outside of math, so it obviously wasn't for lack of trying. But no offers to help or asking what was wrong just you got a bad grade your grounded until your next report card.
Anyways, all of that is to say, I stay involved with my kids school work. Not to a helicopter parent level, but I check with them daily if they have homework, and make sure they know they can come to me if they need help. I remember the first time my daughter failed a test, I didn't yell and she didn't get in trouble. We sat down at the table and reviewed it, and made sure she understood it by the end of the night.
Both of my kids get wonderful grades and I reinforce to them that their hard work is what got them those grades, and reward them for it. Not punishment for bad grades.